Abstract. In this talk, we will state that for perturbed planar polynomial vector fields of degree n (>3) having Z_q-equivarance, by using Mape and the method of detection functions posed by us in 1983 to compute the bifurcation parameter values of Hopf, homoclinic, heteroclinic bifurcations and the bifurcation direction values, under given control conditions, we can find more limit cycles and different configurations of limit cycles. We shall give some examples to introduce the method of parameter controls. A published result in a reference will be corrected.